I have a Joying android radio set in my car on which I happily use Mapfactor. To get HD Traffic Information information I have to create a WiFi hotspot on my phone and connect my unit to it. That way I can download/get HD Traffic information.
However, a WiFi hotspot is a real battery drainer as it is always on and WiFi is an energy expensive option.
Already many, many years before Wifi hotspots, bluetooth tethering was there to share "some" network connection via Bluetooth. Actually that is what I want to do as well with my phone towards my unit. (and that is what you did 15-10 years ago if your laptop did not have WiFi: buy a cheap Bluetooth dongle).
Bluetooth is a low-energy protocol, especially with the new LE and HLE implementations. Using the data connection on my phone in combination with bluetooth tethering is much more battery friendly.
I know Bluetooth is slower, but it is still factors faster than needed for HD Traffic information, also in combination with Music over the same Bluetooth connection (even with HQ flacs).
However, Mapfactor doesn't check for a data connection. It checks for a WiFi connection. To me that is not the correct approach.
Google Maps and MagicEarth for example, simply check for a data connection. As long as they can connect to the internet it is fine. Google Maps takes of course too much data as online nav app*, but MagicEarth only uses it for TMC as well (although you can configure other options as well).
So concluding: Please change the WiFi check into a data/connection check. That can even be a "dirty" approach: Leave the current WiFi check in place and simply extend with "if no WiFi"-> if "data connection" .. -> else "tell the user we can't access HD Traffic".
Maybe I am currently the only one requesting this (I can understand that), but promoting a low energy Bluetooth connection over a battery draining WiFi hotspot connection might get more users interested (In case they simply didn't know :) )
(*: I know Google Maps can nowadays be used offline as well with some restrictions, but in that case you don't get Traffic Info either)
Edit: Updated. Incorrectly used TMC instead of HD Traffic.
May be, but hdwolf's car set obviously does not have a (mobile!?) data connection but only wifi and bluetooth for data transfer. So it does not help him, that his phone may connect via mobile data to the hd traffic servers, what it certainly does. In order to get the hd traffic data to the car set, he has to use his mobile phone and a kind of transmitter of hd traffic data from the mobile data connection of the phone to the car set. This link between the phone and the car set may be wifi or bluetooth (tethering). So it is not simply a question, what the phone has.
When switching on Bluetooth tethering on Android 6.0+ you have to specify on the "receiving" device, in this case the android head unit in my car, that you want to use the connection for "share/use internet connection" as well.
I had forgotten to specify that.
I had paired the car unit with the phone, and then autoconnected the bluetooth-tethering.